Pontiac Solstice Forum - View Single Post - Phoenix Racing... [suspension, springs, and tires discussion]

I sure am glad that this thread has popped back up again. Now that autocross season is in full furry there must be some knowledge being acquired that can be shared. So .....

Earlier in this thread the issues of sway bars came up. Someone mentioned going to a softer configuration on the front through either stiffening the FE2 bar or softening the FE3 bar. Well, in a separate thread I mentioned that I thought that a softer bar might help, caught flack about it, and bought a used FE2 bar for $50 with hardware to try it out. If nothing else, I learned a few things, not the least of which that some rearrangement of bar rates would help but since we can not do anything with the rear bar in Solo2 stock classes it seems to maybe be a stalemate. Why? I feel that the back needs to be stiffened somewhat to keep the car squared up somewhat. I have seen a lot of pictures of my car in action with both the FE3 and FE2 front bars. With the FE2 bar the front showed retention of negative camber (outside wheel) in turns but the car was now leaning so much that the rear wheel appeared to have lost ALL negative camber (and may have been rolled over past 0 to positive). With the 3 bar the car was flatter and cornering forces we controlled to the point where the rear outside wheel appeared to be square to the ground under load. The 2 bar caused the car to become completely tail happy, and adjusting pressures and style to control it cost me a great deal of time on course. But it certainly did accelerate my learning curve on this car. So when the 3 bar went back on I picked up the lost time and THEN SOME!!! Single digit PAX times are there to prove it. So, in the absence of choices, I have drilled another hole inboard of the stock hole on the FE3 bar and after this past weekends two day Salina Divisional I will try the new holes at Heartland Park this coming Sunday. If this causes more push (and I suspect it may) tire pressure and driving adjustment may cover that. A slightly firmer REAR bar could be the ticket for flattening the car even more, but ........... we can't do that YET. Here is the letter I sent SCCA last week (and I was told Saturday that they are looking at both items seriously)

From: Bob Buxbaum [mailto:snaponbob@comcast.net]
Sent: Tuesday, May 22, 2007 12:27 PM
To: Doug Gill
Subject: Rules changes

There are two items I would like considered for the 2008 Solo2 rules;

1) Pontiac Solstice GXP / Saturn Sky Redline to be moved from A/Street Prepared to B/Street Prepared. The reasoning behind this proposed change is that there is no practical way to modify these cars to be competitive against such cars as Lotus Elise, Exige, and Europa, various Porsches, and C5/C6 (inc. ZO6 versions) that come out of S/S. It would seem that if the various "rallye" cars, Honda S2000's, and other A/Stock go to B/SP, then the 2.0 turbo Kappas should be there are well. Even in B/SP the turbo Kappas would be handicapped by the same gearing problems seen in A/Stock as well as engineered controls within the computer that has all but eliminated software "tunes". (I know a lot of people nationally that own GXPs and Redlines and many have said that there is simply not a reasonable opportunity to be competitive in A/SP.)

2) Rule 13.7 restricts sway bar changes to the front ONLY. This is a very old rule that seems to have come about when most cars had either one, or no, sway bar. Over many years cars have become much more sophisticated, with many having sway bars front and rear. In many cases increasing OR decreasing the front bar rate is a backward step, when in actuality the rear bar needs attention. Therefore, I would like to propose that 13.7 be changed to allow ONE sway bar may be changed, added, or deleted, but not both. This would allow the suspension to be tuned, but the choice of tuning could expanded. It seems that this would bring the rules in line with the evolution in suspensions over the past ~20 years and state within the spirit of 13.7.

Thank you for your attention. If you have questions, please contact me.

Bob Buxbaum Lee's Summit, Mo.

I am anxiously awaiting the Koni SA shocks for the Kappas. I have been using adjustable shocks on my last three autocross cars and a lot can be done with them, even single adjustables.

All in all, with the pressures right, and properly driven (I'm working on that with some noticeable improvements) the limits on this chassis are pretty damn high. Now, if I could only "lock" the shoulder belt. The CG Lock is locking the lap portion, but the should belt is just flapping in the breeze, and I like be belted up tight.

__________________
Redline (pre-halt), Pearl, Black/Red
complete option list except auto, 3" MF cat-back,
painted calipers, owner installed power lock buttons

	snaponbob Member Join Date: Jun 2006	I sure am glad that this thread has popped back up again. Now that autocross season is in full furry there must be some knowledge being acquired that can be shared. So ..... Earlier in this thread the issues of sway bars came up. Someone mentioned going to a softer configuration on the front through either stiffening the FE2 bar or softening the FE3 bar. Well, in a separate thread I mentioned that I thought that a softer bar might help, caught flack about it, and bought a used FE2 bar for $50 with hardware to try it out. If nothing else, I learned a few things, not the least of which that some rearrangement of bar rates would help but since we can not do anything with the rear bar in Solo2 stock classes it seems to maybe be a stalemate. Why? I feel that the back needs to be stiffened somewhat to keep the car squared up somewhat. I have seen a lot of pictures of my car in action with both the FE3 and FE2 front bars. With the FE2 bar the front showed retention of negative camber (outside wheel) in turns but the car was now leaning so much that the rear wheel appeared to have lost ALL negative camber (and may have been rolled over past 0 to positive). With the 3 bar the car was flatter and cornering forces we controlled to the point where the rear outside wheel appeared to be square to the ground under load. The 2 bar caused the car to become completely tail happy, and adjusting pressures and style to control it cost me a great deal of time on course. But it certainly did accelerate my learning curve on this car. So when the 3 bar went back on I picked up the lost time and THEN SOME!!! Single digit PAX times are there to prove it. So, in the absence of choices, I have drilled another hole inboard of the stock hole on the FE3 bar and after this past weekends two day Salina Divisional I will try the new holes at Heartland Park this coming Sunday. If this causes more push (and I suspect it may) tire pressure and driving adjustment may cover that. A slightly firmer REAR bar could be the ticket for flattening the car even more, but ........... we can't do that YET. Here is the letter I sent SCCA last week (and I was told Saturday that they are looking at both items seriously) From: Bob Buxbaum [mailto:snaponbob@comcast.net] Sent: Tuesday, May 22, 2007 12:27 PM To: Doug Gill Subject: Rules changes There are two items I would like considered for the 2008 Solo2 rules; 1) Pontiac Solstice GXP / Saturn Sky Redline to be moved from A/Street Prepared to B/Street Prepared. The reasoning behind this proposed change is that there is no practical way to modify these cars to be competitive against such cars as Lotus Elise, Exige, and Europa, various Porsches, and C5/C6 (inc. ZO6 versions) that come out of S/S. It would seem that if the various "rallye" cars, Honda S2000's, and other A/Stock go to B/SP, then the 2.0 turbo Kappas should be there are well. Even in B/SP the turbo Kappas would be handicapped by the same gearing problems seen in A/Stock as well as engineered controls within the computer that has all but eliminated software "tunes". (I know a lot of people nationally that own GXPs and Redlines and many have said that there is simply not a reasonable opportunity to be competitive in A/SP.) 2) Rule 13.7 restricts sway bar changes to the front ONLY. This is a very old rule that seems to have come about when most cars had either one, or no, sway bar. Over many years cars have become much more sophisticated, with many having sway bars front and rear. In many cases increasing OR decreasing the front bar rate is a backward step, when in actuality the rear bar needs attention. Therefore, I would like to propose that 13.7 be changed to allow ONE sway bar may be changed, added, or deleted, but not both. This would allow the suspension to be tuned, but the choice of tuning could expanded. It seems that this would bring the rules in line with the evolution in suspensions over the past ~20 years and state within the spirit of 13.7. Thank you for your attention. If you have questions, please contact me. Bob Buxbaum Lee's Summit, Mo. I am anxiously awaiting the Koni SA shocks for the Kappas. I have been using adjustable shocks on my last three autocross cars and a lot can be done with them, even single adjustables. All in all, with the pressures right, and properly driven (I'm working on that with some noticeable improvements) the limits on this chassis are pretty damn high. Now, if I could only "lock" the shoulder belt. The CG Lock is locking the lap portion, but the should belt is just flapping in the breeze, and I like be belted up tight. __________________ Redline (pre-halt), Pearl, Black/Red complete option list except auto, 3" MF cat-back, painted calipers, owner installed power lock buttons